Pressure vessel with flushing device

The invention relates to a pressure vessel, having: a reaction chamber (2) as a pressure space for the initiation and/or facilitation of chemical and/or physical pressure reactions of samples (P) accommodated in the reaction chamber (2); a fluid inlet (20) with a feed valve (21) which is adjustable between an open position, for the feed of a fluid, preferably a flushing gas, into the reaction chamber (2), and a closed position, for stopping the feed of the fluid; a fluid outlet (30) with a discharge valve (31), which is adjustable between an open position, for the discharge of a fluid out of the reaction chamber (2), and a closed position, for stopping the discharge of the fluid out of the reaction chamber (2); and an oxygen sensor (33) for detecting an oxygen content in the reaction chamber (2). The pressure vessel (1) furthermore has a control device which is configured to control the feed valve (21) and the discharge valve (31) on the basis of the oxygen content detected by the oxygen sensor (33), such that the reaction chamber (2) is flushed via the feed and discharge valves (21, 31) situated in the open position, and at least the discharge valve (31) switches from the open position into the closed position as soon as a predetermined oxygen content is undershot. The invention also relates to a corresponding method.